Page:Scientific results HMS Challenger vol 18 part 2.djvu/164

1040 6. Dendrospyris ramosa, n. sp.

Shell nut-shaped, spiny, with irregular roundish pores. Basal plate with three pairs of pores. Apical horn cylindrical, spinulate, twice to three times as long as the shell. Feet as long as the horn, S-shaped, widely divergent, irregularly branched, with widely distant pointed branches.

Dimensions.—Shell 0.08 long, 0.12 broad; horn and feet 0.2 to 0.3 long.

Habitat.—North Atlantic, Station 353, depth 2965 fathoms.

7. Dendrospyris arborescens, n. sp. (Pl. 85, fig. 9).

Shell nut-shaped, tuberculate, with subregular circular pores. Basal plate with four central larger and ten to twelve peripheral smaller pores. Apical horn cylindrical, twice as long as the shell, in the distal half spinulate or tuberculate. Feet about three times as long as the shell, cylindrical, nearly vertical, in the distal half irregularly branched, with dense bunches of aggregated blunt branches.

Dimensions.—Shell 0.07 long, 0.09 broad; horn and feet 0.12 to 0.18 long.

Habitat.—Equatorial Atlantic, Station 347, depth 2250 fathoms.

Definition.— with two free lateral feet armed with a series of secondary spines. Apex with a horn.

The genus Dorcadospyris and the closely allied Stephanospyris differ from the other Dipospyrida in the development of a series of secondary spines on the convex outer margin of the two large curved lateral feet, which therefore appear semipinnate. In some species this peculiar armature attains an extraordinary size, whilst the shell itself is very small, as in Dorcadospyris dinoceras (Pl. 85, fig. 4).

1. Dorcadospyris dentata, n. sp. (Pl. 85, fig. 6).

Shell subspherical, tuberculate with small regular circular pores. Basal plate with four larger pores. Apical horn three to four times as long as the shell, slender conical, smooth. Feet more or less convexly curved towards one another; the distal ends not crossed. In the convex edge of each arm a series of five to ten smooth conical teeth, not longer than the shell. This common species is very variable and often asymmetrical; the figured specimen is an asymmetrical one, in which the two arms exhibit different curves; in the normal form both arms have the same curve, now more, now less convex.

Dimensions.—Shell 0.06 long, 0.08 broad; horn 0.2, feet 0.03 long.

Habitat.—Central Pacific, Stations 267 to 274, depth 2350 to 2925 fathoms.